U.S.S. Rhode Island Classification?

The "U.S.S. Equinox" from ST:VOY was described in general as a science vessel, and somewhat more specifically as a planetary research ship. Although to me personally, she always seemed like a general purpose small starship at heart, with this variant of the design maybe configured more for research. Afterall, unofficially her design started out as a small warship that ultimately lost out to the "Defiant". Anyway...

In the final episodes, we see the "U.S.S. Rhode Island" which is obviously a variant of the same design, yet seems to be more combat capable. My question is, if you had to classify this ship, what would it be? And what would her mission profile include? Just curious to see what others think.

And if you think that the "Rhode Island' we saw onscreen had undergone a significant refit sometime in the past, (I tend to assume she was originally built not long after the original Nova class, though there's nothing to support that...just my own speculation) what do you think her classification and mission profile was originally?

- If you want easily associable late 20th century, corvette is probably the way to go. Those are the warships the most closely matching small survey ships of today in size and design.
- If you want WWII, some sort of an escort might be your bet. The Flower corvettes were essentially armed whalers, while the assorted sloops and frigates of the era were more like miniature destroyers, so again corvette might get my votes. But that's sort of British - destroyer escort would be the American option, although it sounds clumsy to me.
- You can go back to the sailing days, too - the Royal Navy certainly did when "inventing" names for its innovative WWII vessels. A Starfleet sloop or brig might sound funny, though, to modern ears.
- Perhaps the tiny vessel isn't really a ship (save in the sense a runabout can be called "starship" by a pompous pilot), though. "Patrol boat" would be quite fitting, too.

Ships of the same class can be utilized for different purposes. Take the Miranda class. Throughout its appearances in Trek, it's been used as a science vessel, a transport/freighter, and a ship of the line.

Furthermore, a ship can be a science vessel and also have badass weaponry at the same time.

My vote would be a Perimeter Action Vessel. High speed, moderately armed (compared to other ships its size), small, maneuverable and able to quickly engage in border patrol and interdiction missions. IMO, too small to be a frigate.